Ice breaking apparatus and method



Nov. 21, 1961 w. w. CUSHMAN ICE BREAKING APPARATUS AND METHOD 5Sheets-Sheet 1 Filed Nov. 20. 1959 INVENTORQ w. w. CUSHMAN 6. G wm.

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A TTORNE Y Nov. 21, 1961 w. w. CUSHMAN ICE BREAKING APPARATUS AND METHOD3 Sheets-Sheet 2 Filed Nov. 20. 1959 FIG.3

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A TTORNE Y Nov. 21, 1961 w. w. CUSHMAN 3,009;434

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A TTORNEY United States Patent ()fiiice Patented Nov. 21, 1961 3,009,434ICE BREAKING APPARATUS AND METHOD Walton W. Cushman, 401 N. Penn St.,Webb City, Mo. Filed Nov. 20, 1959, Ser. No. 854,430 17 Claims. (Cl.114-40) This invention relates to a method of and apparatus for breakingice and opening ice-bound navigable waters.

An object of the invention is to provide a novel and improved method andapparatus for ice breaking, which is not dependent upon the propulsiveforce 'of the rather inefficient screw propeller employed onconventional ice breaking ships, and including means for directengagement with the ice to positively propel the apparatus therethrough,while simultaneously breaking the ice and discharging it at the side ofthe open channel.

A further object is to provide a method and apparatus of theabove-mentioned character which utilizes the buoyancy of a float bodyportion under the ice, in conjunction with positive propelling meansengageable with the bottom surface of the ice to break the ice.

A further object of the invention is to take advantage of the relativeweakness of the ice under bending stresses for breaking it, instead ofresorting to the application of compressive and shearing stresses,against which the ice is highly resistant.

A further object is to provide a method of ice breaking which includesadvancing a forwardly tapering wedgelike float body portionprogressively under the ice to impart to the ice an increasing upwardthrust which breaks the ice, and then conveying away the broken ice withthe means employed to propel the float body portion under the ice.

A further object of the invention is to discharge the broken ice on topof the unbroken ice, at one or both sides of the navigation channel,instead of forcing the broken ice beneath the unbroken ice where thetemperature of the water is not below the freezing point.

Another object of the invention is to provide an ice breaking apparatusin the nature of an amphibious vehicle having means to propel and steerthe same on the land, in the water, and while engaging the ice.

A further object of the invention is to provide means for readilyflooding any or all of the buoyant tanks of the apparatus with water tofacilitate submerging them beneath the ice, as well as means fordischarging water from the tanks and pressurizing them with compressedair.

Another object of the invention is to provide an ice breaking apparatusincluding a wedge-like float body portion which is articulated, so thata portion or portions only of the float body portion may be caused topass under the ice, while remaining sections of the float body portionextend above the ice.

A further object is to utilize positively acting frictional propellingmeans for the apparatus which directly engage the relatively soft bottomsurface of the ice, at or near the freezing temperature of the water.

A still further object is to provide ice breaking apparatus which may bebuilt largely from parts that are readily available upon the market, andthereby rendering the apparatus practical and relatively economical tomanufacture, compared to conventional ice breaking equipment.

Other objects and advantages of the invention will be apparent duringthe oourse of the following detailed description.

In the accompanying drawings, forming a part of this application and inwhich like numerals are employed to designate like parts throughout thesame,

FIGURE 1 is a partly diagrammatic side elevation of an ice breakingapparatus embodying the invention and illustrating the same floating inthe Water.

FIGURE 1 is a plain view of the apparatus shown in FIGURE 1.

FIGURE 3 is a further side elevation of the apparatus illustrating theuse of the same during the practice of the method.

FIGURE 4 is a rear end elevational view of the ice breaking apparatus.

FIGURE 5 is an enlarged fragmentary plan view of the apparatusillustrating the arrangement of the propelling and conveyor chains uponadjacent tanks of the apparatus.

FIGURE 6 is an enlarged fragmentary longitudinal vertical sectionthrough one float unit or tank of the apparatus and the propelling andconveying chains associated with such tank.

FIGURE 7 is a fragmentary vertical section taken on line 77 of FIGURE 6.

FIGURE 8 is a partly diagrammatic vertical section through a companionpair of tanks and associated elements of the apparatus, and illustratingstructure which is typical of or common to the other pairs of tanks ofthe apparatus, except the tanks which contain the prime movers andassociated equipment.

FIGURE 9 is a similar partly diagrammatic sectional view of the tanksand associated elements carrying the prime movers of the apparatus andassociated equipment.

FIGURE 10 is a transverse vertical section taken on line iii-10 ofFIGURE 9.

FIGURE 11 is a diagrammatic plan view illustrating the compressed airand suction circuit for the apparatus and the control means therefor.

In the drawings, wherein for the purpose of illustration is shown apreferred embodiment of the invention, the numerals 15 and 16 designateside-by-side longitudinal groups of floats or tanks which togetherconstitute the float body portion of the ice breaking apparatus. Thetanks of the groups 15 and 16 are all cylindrical and have theirlongitudinal axes arranged parallel and extending transversely of theline of travel of the apparatus when the same is in use. Companiontransverse pairs of tanks in the longitudinal groups 15 and 16 arearranged in axially opposed spaced relation and in alignment.

Each longitudinal group 15 and 16 comprises tanks 17, 18, 19, 20, 21 and22 of equal axial length, and of successively smaller diameter towardthe forward or leading tank 22 of the group. The rearmost tank 17 ofeach group 15 and 16 may be about twenty-four feet in diameter, whilethe forwardmost tank 22 may be about six feet in diameter. Theintermediate tanks are of diameters to render the groups of tanksuniformly forwardly tapering or wedge-like, as clearly shown inFIGURE 1. The diameters and lengths of the several tanks may be variedsomewhat in practice, and the above suggested diameters are by no meanscritical and merely illustrative of the contemplated size of theapparatus. However, the proportions and relative sizes shown in thedrawings illustrate the preferred overall configuration of the floatbody portion composed of the several tanks. As illustrated, the axiallength of each tank is preferably somewhat greater than the diameter ofthe largest tank 17, see FIGURE 2.

The tanks employed in the apparatus are preferably formed of steel andare of a type readily available on the market. Relatively thin walledsteel tanks are adequately strong and rigid for the proposed usage,particularly in view of the fact that the strength of each tank may bematerially increased by the use of relatively low internal air pressure,in a manner to be further described.

With particular reference to FIGURE 6 each of the mentioned steel tanksin the groups 15 and 16 has an outer covering 23 of rubber or the likeupon its periphery and suitably fixedly secured thereto to form aresilient external cushion. The covering 23 is formed to provide aplurality of equidistantly spaced annular ribs 24, integral therewith,forming annular grooves 25 therebetween, as shown.

The apparatus further comprises articulated interconnecting means forthe tanks in the longitudinal groups and 16. This means comprises a pairof side longitudinal articulated beams 26 and 27 arranged near andparallel to the outer end Walls of the tanks in groups 15 and 16, seeFIGURE 2.

As typically illustrated in FIGURE 8, each companion or lateral pair oftanks has a hollow non-rotatable cylindrical axle 28 of considerablediameter extending axially therethrough and somewhat outwardly of theouter ends of the tanks of the Particular pair. Each tanks is freelyrotatably mounted upon its axle 28 through the medium of combinedbearings and packing glands 29 of conventional construction, and heldwithin housing means 30, carried by the tank end walls 31. The bearingmeans 29 snugly engages the axle 28 and serves adequately to hold eachtank against endwise movement upon its axle.

While the tanks 21 have been chosen at random for illustration withtheir axle 28 in FIGURE 8, it should be understood that this view istypical of the mounting of all companion pairs of tanks of theapparatus, with the exception of the tanks 19 shown in FIGURE 9. Thetanks 19 shown in FIGURE 9 contain prime movers and associated equipmentto be described hereinafter. These tanks have a modified form ofcylindrical tubular axle 32 including a greatly enlarged central portion33, common to the two tanks 19 as shown in FIGURE 9. The tanks 19 arefreely rotatably mounted upon the axle 32 by combined bearing andpacking gland means 34 and 35, generally similar to the means 29previously described in connection with the other tanks of theapparatus. The bearing means 35 is larger than the bearing means 34 toaccommodate the enlarged hollow axle portion 33, FIGURE 9. The axle 32is non-rotable like the other axles 28 of the apparatus. The ends of theaxle 32 also project outwardly of the outer ends of the two tanks 19, asshown.

Returning at this point to the articulated beams 26 and 27, each suchbeam comprises a first or rearmost beam section 36, having its rear endapertured to receive one end portion of the axle 28 for the largest pairof tanks 17. The forward end of each rearmost beam section 36 carries apair of spaced apertured knuckles 37, adapted to receive therethroughrotatably the end portions of the axle 28 of the companion pair of tanks18.

The beams 26 and 27 further comprise second beam sections 38 having rearand forward reduced apertured extensions 39 and 40, receivingrespectively the ends of the axle 28 for the tanks 18 and the ends ofthe modified axle 32 for the tanks 19. The apertured extensions 40 ofthe beam sections 38 are rigid with the ends of the axle 32 and are notpivoted to such axle. The extensions 39 are also rigidly secured to theadjacent axle 28 by means of hollow cap screws 41, shown in FIGURE 2,and typically illustrated in FIGURE 8. Identical cap screws 41, FIGURE4, also serve to rigidly secure the rear ends of the first beam sections36 to the axle 28 of the largest pair of tanks 17. The forward knuckles37 of the beam sections 36 are however freely .pivotally mounted uponthe ends of the axle 28 for the pair of tanks 18.

The beams 26 and 27 further comprise third beam sections 42, each havinga rear semi-circular collar section 43 formed integral therewith aforward reduced apertured extension 44 receiving one end of the axle 28for the pair of tanks 20. Each extension 44 is rigidly secured to theadjacent axle 28 and held against rotation relative thereto by one ofthe mentioned cap screws 41.. Each rear collar section 43 has rigidlysecured to it a companion collar half or section 45, and the annularcollar formed by the connected collar sections 43 and 45 pivotallyreceives the end portions of the modified axle 32 for the tanks 19.

The beams 26 and 27 further comprise fourth beam sections 46 having rearspaced apertured knuckles 47 and forward reduced apertured extensions 48integral therewith. The knuckles 47 pivotally receive the ends of theaxle 28 for the tanks 20, and the extensions 48 are held rigid with theends of the axle 28 for the tanks 21 by means of the mentioned hollowcap screws 41.

The articulated beams 26 and 27 further include fifth and forwardmostbeam sections 49, having their forward ends apertured to receive theends of the axle 28 of the forwardmost tanks 22. The beam sections 49are rigidly secured to the forwardmost axle 28 by a pair of the capscrews 41. At their rear ends, beam sections 49 carry spaced aperturedknuckles 50 integral therewith, and pivotally receiving the end portionsof the axle 28 for tanks 21. The knuckles 50 are arranged upon oppositesides of the extensions 48 as shown in FIGURE 2.

The construction of the articulated float body portion of the apparatusshould now be clear. The rearmost pair of tanks 17 with their axle 28and the beam sections 36 are pivotal or vertically swingable about theaxle 28 of the tanks 18 through the medium of the hinge knuckles 37. Therear ends of the beam sections 36 are rigid with the rearmost axle 28 sothat the latter cannot r0- tate. The tanks 18 and 19 and theirrespective axles 28 and 32 are rigid or non-articulated relative to eachother because the beam sections 38 have their rear ends rigidly securedto the axle '28 for the tanks 18, and their forward ends rigid with theaxle 32. The tanks 20 with their axle 28 are articulated or verticallyswingable about the axle 32, through the medium of the collar sections43 and 45. The forward ends of the beam sections 42 are rigid with theaxle 28 for the tanks 26. The tanks 21 with their axle 28 are verticallyswingable or articulated with respect to the tanks 20, due to thepivotal connection of the knuckles 47 upon the adjacent axle 28 fortanks 20. The forward ends of the beam sections 46 are rigid with theaxle 28 for the tanks 21. The forwardmost tanks 22 with their axle 28are vertically swingable upon the axle of the tanks 21, due to thepivotal engagement of the knuckles 50 with the axle for the tanks 21.The forward ends of the beam sections 49 are rigid with the axle 28 ofthe forwardmost tanks 22, as stated.

Combined apparatus propelling and broken ice conveyor chains engage thetanks of the groups 15 and 16 in a manner to be now described. Thesechains are preferably of the silent sprocket chain type including links51 and 52, FIGURE 7, the former links being provided with pointedprojections or teeth 53, equidistantly spaced apart along the lengths ofthe endless chains. In the present apparatus, these chains are mountedupon the several tanks with their teeth 53 projecting outwardly orradially of the tanks, and this arrangement is the reverse of the mannerin which the silent chains operate upon the usual sprocket wheels. Asshown in FIGURE 6, the chains operate within the grooves 25 between theannular ribs 24 of the resilient coverings 23, and the ribs 24 serve toguide the chains during their operation.

With particular reference to FIGURES 2 and 5, the driving or prime movercontaining tanks 19 carry laterally spaced sets of endless chains 54 and55 which extend respectively about the peripheries of the tanks 20 and18, forwardly and rearwardly of the tanks 19. The chains 54 and 55driven by the prime mover containing tanks 19 are thus adapted todirectly drive the tanks 20 and 18 in unison and in the same directionwith the tanks 19. Similar sets of laterally spaced chains 56 and 57engage about the tanks 20 and 21 and the tanks 18 and 17 of each groupof tanks to drive the same in unison with the tanks 19. As shown in thedrawings, the chains 56 and 57 are staggered laterally with respect tothe previously described chains 54 and 55. Similar sets of endlesschains 58 span the peripheries of the tanks 21 and 22 of each group and16 to drive the forwardmost tanks 22 in unison with all of the othertanks of the apparatus. The chains 58 are staggered laterally withrespect to the chains 56 as shown.

As shown in FIGURE 2, the endmost pairs of tanks 17 and 22 have only onegroup or set of chains 57 and 58 connected therewith, whereas all of theother tanks in the apparatus have two sets of chains engaging therewith.Consequently, alternate grooves 25 in the rubber coverings of theendmost tanks 17 and 22 are empty, whereas all of the grooves 25 of allother tanks of the apparatus are occupied by the chains. The describedsets of endless chains thus connect and directly drive only two adjacenttanks in the groups 15 and 16, although the arrangement of chains issuch that all tanks of the apparatus are adapted to be driven in unisonand in the same direction when the tanks 19 are rotated by the primemover means to be described. The multiplicity of endless chains providesa broad and substantially uninterrupted conveyor bed extending over thetops of all of the tanks in the two groups 15 and 16, and the conveyorbeds are inclined upwardly and rearwardly on the wedge-shaped float bodyportion as shown in FIGURE 1.

With particular reference to FIGURES 9 and 10, each tank 19 of theapparatus contains a prime mover 59, such as a large diesel engine, anelectrical generator 6!) and a large air compressor and suctionproducing unit 61. These elements 59, 60 and 61 are individuallyconventional in construction and need not be described in detail herein.The engine, generator and compressor means within each tank 19 arepreferably unitized in assembly and rigidly and fixedly secured to thenon-rotatable tubular axle 32 by suitable bracket means 62, as shown inFIGURE 9. Each engine 59 has suitable built-in gear speed reducer meansnot shown including an output or driving pinion 63, FIGURE 10, inconstant mesh with a large ring gear 64, secured within each tank 19, asshown diagrammatically in the drawings. Consequently, operation of eachengine 59 imparts rotation to one of the pinions 63, which in turndirectly drive each tank 19 through the medium of the ring gear 64. Eachengine 59 also drives or operates one generator 60 and one combined aircompressor and suction device 61, as shown diagrammatically in FIGURE 9.

The engines 59, which are reversible, are thus adapted to drive all ofthe tanks 17-22 in the groups 15 and 16 in unison and in the samedirection, through the medium of the previously described combinedpropulsion and conveyor chains 54 through 58.

An elevated transversely elongated horizontal control platform 65 issupported above the rearrnost pair of tanks 17 by legs 66, which havetheir lower ends pivotally secured to the extremities of the rearrnostaxle 28, as at 67, FIGURE 4. The platform 65 is stabilized by a pair ofdiagonal adjustable telescopic struts 68, preferably of a conventionalhydraulic type, and adapted to be extended or contracted by suitableconventional hydraulic control means, not shown, located upon the plat-Imounted'upon the rearrnost axle 28 at 73, FIGURE 4.

The motors 71 are thus arranged at the rear of the apparatus and uponopposite sides of the same, as shown. The motors 71 drive screwpropellers 74, which serve to propel the apparatus in the water, priorto engagement with the ice to be broken. The arms 72 are retractable forelevating the propellers 74 from the water during the ice breakingoperation or during'travel of the apparatus over land, by any suitablefluid pressure operated retracting mechanism 75. Conventional controlsfor the mechanism 75, not shown, are located upon the platform 65.

The electric motors 71 are energized by current produced by theelectrical generators 60, driven by the engines 59. The wiring betweenthe generators and motors 71 is conventional and has been omitted fromthe drawings for the purpose of simplification. The engines 59 areindependently controlled by conventional remote control means, notshown, and also located upon the platform 65.

Adjacent the tops of the rearrnost tanks 17 and just rearwardly of theirtops, a transversely extending elongated broken ice conveyor chute 76 isprovided. The chute 76 is rigidly connected to the legs 66 by suitablerigid bracket means 77. As best shown in FIGURE 4, the ice chute 76 issomewhat inclined downwardly from the center of the apparatus at 78 andhas a pair of inclined discharge extensions 79 which projectsubstantially outwardly of the opposite sides of the apparatus forconveying the broken ice laterally thereof and depositing the broken iceon top of the unbroken portions 80 of the ice mass, on opposite sides ofthe navigation channel 81 formed through the ice by the apparatus. Ifpreferred, the ice chute 76 may be constructed to discharge ice at oneside only of the apparatus. As illustrated, the ice chute 76 receivesbroken ice from the upper runs of the conveyor chains of both sets oftanks 15 and 16 and discharges the broken ice a substantial distancebeyond the opposite sides of the channel 81.

With continued reference to the drawings, particularly FIGURE 8, eachhollow axle 28 has its opposite ends closed at 82 and its interiordivided between the companion pair of tanks rotatably mounted thereon bya fluid tight transverse web 83. The web 83 thus divides each axle 28into two non-communicating interior chambers 84 and 85. An upstandingopen pipe 86 is rigidly secured within an opening in the axle 2'8 andprojects near the top of each tank carried by the particular axle. Eachpipe 86 communicates directly with the interior of the adjacentcylindrical tank and with one of the axle chambers 84 or 85. An invertedU-shaped pipe 87 is provided for each tank of the apparatus, except theprime mover containing tanks 19, which do not have either of the pipes86 or 87. Each pipe 87 has a depending vertical leg 88 extending closeto the bottom of the adjacent tank and being in direct communicationwith the interior of such tank and passing through an opening 89provided in the axle 28. Each pipe 87 also includes an externaldepending vertical leg 90, preferably formed of rubber or the like, andterminating somewhat below the bottom of the associated tank. The legs88 and 90 are integrally connected with a horizontal pipe section 91,within the chambers 84 or 85, and having a conventional remotelycontrolled solenoid operated valve 92 connected therein, as shown. Eachvalve 92 may be opened or closed by conventional control means, notshown, preferably located somewhere on the platform 65.

The construction thus far described in connection with FIGURE 8 istypical for all tanks of the apparatus except the tanks 19 shown inFIGURE 9, as previously stated.

With reference to FIGURE 9, the hollow axle 32 has its opposite endsclosed at 93, and the axle 32 is provided with large openings 94,serving to place the interior of the axle 32 in direct communicationwith the interiors of the prime mover containing tanks 19.

A very large combined air duct and enclosed catwalk 95 has its forwardend rigidly secured to and opening into the central enlargement 33 ofthe hollow axle 32. The air duct 95 is inclined upwardly and rearwardlyand extends between the groups of tanks 15 and 16, as shown. As shown inFIGURE 4, the rear open end 96 of the duct 95 preferably terminatesadjacent to the rear side of 7 the ice chute 76 and just below thelatter. The rear end portion of the duct 95 may be suitably rigidlysecured to the ice chute structure in any preferred manner. The duct 95is spaced above the axles 28 of the tanks 17 and 18 as shown in FIGURE1.

The proportions of the air duct 95 and shaft 32 are such that a workmanmay climb into the rear end of the duct 95 and walk down through thesame to the enlarged portion 33 of axle 32, and this workman may thenclimb through either opening 94 to gain access to the interior of eithertank 19, for servicing the equipment therein. Suitable ladders, notshown, may be provided upon the apparatus to facilitate the passage ofthe workman from the control platform 65 into the prime mover tanks 19.

With continued reference to the drawings, and particularly diagrammaticFIGURE ll, a large suction hose 97 and a companion compressed air hose93 leads from the combined suction and air compression unit 61 of eachtank 19. These hoses extend through the openings 94 and through the airduct 95 to the platform 65, where they are connected with selectorvalves 99, housed or protected by box structures 10% on the platform 65.The selector valves 99 are ten in number and arranged in two groups offive each, FIGURE 11, corresponding to the number of tanks in the groupsand 16 excluding the tanks 19. Each selector valve 99 is connected witha hose 101 which leads to one of the hollow cap screws 41 shown inFIGURE 8. As shown in FIGURES 1 and 8, the end of each hose 101 remotefrom its valve 99 is connected with one hollow cap screw 41 in asuitable fluid tight manner, and through this cap screw with oneinterior chamber 84 or 85 of the particular axle 23 having a companionpair of the apparatus tanks other than the tanks 19. Through thechambers 84 and 85, the hoses 1.01 are thus in communication with thepipes 86 and through these pipes with the interiors of the particularrotatable tanks and the U-shaped pipes 87 having the solenoid operatedvalves 92 connected therein.

When the engines 59 are operating to drive the combined compressors andsuction means 61, the manifolds 102 carrying the selector valves 99 arerespectively supplied with compressed air and under vacuum through themedium of the hoses 98 and 97. Consequently, when the operator throwsthe handle of any selector valve 99 in one direction, the particularhose 191 connected with such valve may receive compressed air and if thevalve handle is thrown in the opposite direction the hose 101 may beplaced under vacuum. All of the valves 99 in the two groups thus operateindependently for placing their respective hoses 101 in communicationwith air under pressure or with suction. By this means, cornpressed airmay be conveyed through each hose 191 independently to a particularfitting 41 communicating with a chamber 84 or 85, FIGURE 8. Likewise, avacuum may be created within the chamber 84 or 35 through one of thehoses 101 when the particular valve 99 connected with that hose isproperly adjusted.

This compressed air and vacuum system above described is utilized duringthe operation of the apparatus to drive water out of any or all of theseveral tanks, except the tanks 19, or to flood the several tanks with adesired quantity of water.

In order to flood a particular tank or tanks with water, FIGURE 8, thehose or hoses 161 leading to such tanks are placed in communication withsuction by proper manipulation of the valves 99. The solenoid operatedvalve or valves 92 are now opened by remote control means on theplatform 65, and the vacuum within the chambers 84 and 85 and within thetanks 19 will draw water through the inverted U-shaped pipes 87 into thetanks to flood the same with any desired quantity of water. When thevalves 92 are closed, the flooding of the particular tanks with waterwill cease.

When it is desired to expel the Water from a tank or tanks, the chambers84 and 85 receive compressed air from the particular hoses 191, and thisis occasioned by again properly adjusting the associated valves 99.Compressed air from the hoses 101 passes through the chambers 84 and S5and through the upstanding pipes 86 to the tops of the tanks 21, FIGURE8, or any other desired tanks in the groups 15 and 16 except the tanks19. The solenoid operated valves 92 are again opened, and the compressedair above the water in the tanks 21 will force the water through thepipes 87 until the tanks are fully emptied of Water or until the waterlevel is decreased to the extent desired. By this means, substantiallyall water may be expelled from the particular tank or tanks, and theinterior of the tanks may be subjected to positive air pressure of, say,five pounds per square inch, or the like. In this manner, the relativelythinwalled tanks of the apparatus may be rendered much more rigid so asto resist buckling upon contact with the ice or when the apparatus istraveling over land.

In the described manner, each tank of the apparatus except the tanks 19may be independently charged with compressed air to expel watertherefrom or placed in communication with suction to draw water in thesame. This mode of operation is utilized during the practice of themethod to bring the articulated float body portion into properengagement with the ice for breaking it, as will be further described.

The general operation of the apparatus during the practice of the methodis as follows:

The apparatus may be floated in the water as illustrated in FIGURE 1 andpropelled toward the ice to be broken by the propellers 74, driven bythe electric motors 71. While so propelled, all of the tanks havinghoses 101 connected therewith may be emptied of Water or substantiallyemptied and under positive internal air pressure if desired. When thiscondition prevails, the float structure of the apparatus may havemaximum buoyancy so as to ride high upon the water and be relativelyeasy to propel, notwithstanding its great size. During propulsionthrough the water, the engines 59 may be driven in the proper directionfor causing the endless chains to travel in the clockwise direction,FIGURE 1, and this will aid in propelling the apparatus in the water.Steering is accomplished in the water by running the propellers 74' atdifferent speeds or by reversing the direction of operation of one ofthe propellers, and this is controlled remotely by conventional controlmeans upon the platform 65.

When the mass of ice to be broken by the apparatus is arrived at, theleading end of the apparatus is caused to approach the ice mass underthe influence of the screw propellers 74. The selector valve means 99are now operated in the manner described previously to flood or partlyflood the leading two, four or six tanks with Water. This will decreasethe buoyancy of the mentioned tanks sufliciently to enable them to passbeneath the frozen ice in approximately the manner illustrated in FIGURE3. The propellers 74 are still utilized at this time to propel theleading tanks under the ice.

After initial engagement of the leading two or four tanks of theapparatus under the ice, the propellers 74 are retracted from the water,FIGURE 3, and the engines 59 are operated in a direction causing theendless chains to run in a reverse or counter-clockwise direction inFIG- URE 3. Substantially simultaneously, the selector valves 99 areoperated to expel the water from the leading previously flooded tanks,in order to greatly increase their buoyancy. This immediately causes thetanks to exert a very great upward force against the bottom of the ice,while the upper runs of the endless chains are traveling in thedirection of the arrow in FIGURE 3 and their teeth 53 are directlyengaging the bottom of the ice. The bottom of the ice is relatively softand near the freezing temperature of water, and this aids the teeth 53in digging into the ice.

The above action causes the wedge-shaped articulated float body portionto be propelled forwardly underneath the ice and to exert a graduallyincreasing upward force against the ice as additional tanks of increaseddiameter and buoyancy are gradually drawn downwardly under the ice asillustrated in FIGURE 3. A point is soon reached where the ice can nolonger withstand the upward thrust placed on it by the apparatus, andthe ice wlll break upwardly under the bending stresses imparted to it bythe apparatus.

As the ice breaks off progressively into pieces 103, such pieces of thebroken ice are conveyed upwardly and rearwardly by the top runs of thetoothed chains and deposited upon the conveyor chute 76 at the rear ofthe apparatus. The broken ice passes under the platform 65 and isdeposited continuously upon the two sloping sections of the chute 76 bythe chains on the two groups of tanks 15 and 16'. Once the ice is uponthe chute 76, it will immediately slide down the chute and be discharged'on top of the unbroken ice mass 80, outwardly of the channel 81 whichis continuously being formed by the apparatus.

This is a great advantage over forcing the broken pieces of iceunderneath the ice mass 80, as occurs when conventional ice breakingships are employed. When the broken ice is forced beneath the ice masson opposite sides of the channel, it does not freeze because it is in aregion where the water temperature is obviously above the freezingpoint. Consequently, the broken ice may tend to float back into thenavigation channel after the conventional ice breaking equipment haspassed beyond. In my method, the broken ice is deposited by the chute 76on top of the ice mass 80 Where it will quickly freeze in the lowtemperatures prevailing above the ice, and there is no tendency for thebroken ice to slide back into the open channel 81.

The ice breaking process during the practice of the method iscontinuous, and the counter-clockwise movement of the chainscontinuously propels the apparatus along the bottom of the unbroken iceuntil the upward force of the buoyant tanks is such that the ice breaksoff and is conveyed upwardly continuously in the manner described.

With the present apparatus and method, ice of substantially anythickness encountered in known navigable waters may be successfullybroken and conveyed away. If the ice is relatively thin, it may breakupwardly under bending stresses when only the first two or four tanks ofthe apparatus have been propelled beneath it. When thicker ice isencountered, it may be necessary for the first six or eight tanks of theapparatus to be propelled under the ice before it will break upwardly asillustrated in FIGURE 3. It is believed that even the thickest ice willbreak in the manner described, by the time that the relatively largetanks 18 begin to be drawn beneath the ice by the action of the toothedchains.

The apparatus is capable of propelling itself by engagement with thebottom of the ice with approximately the same efficiency that a tracklaying vehicle will travel upon the ground or over snow or the like. Itmay now be seen that during the actual ice breaking process, theapparatus does not depend upon the propulsive force of the screwpropellers 74 which have very limited efliciency, as is well known.

As should now be obvious, the chains on one group of tanks 15 or 16 maybe driven at a different rate of speed and/or in a reverse directionfrom the chains on the other group of tanks. By this means, theapparatus is rendered steerable while engaging the ice or whiletraveling over land.

As just suggested, the apparatus is capable of traveling over land priorto entering the water. While operating over land it is preferred to havethe several tanks pressurized with compressed air in order to renderthem more rigid or sturdy so that they will not tend to buckle.

I contemplate employing hydraulicallyor compressed lb air operatedmeans, not shown, for elevating the leading six tanks 20, 21 and 22 andthe rearmost tanks 17 while the apparatus is traveling over land on onlythe four tanks 18 and 19. However, the apparatus is capable of operatingover land and of being steered while all tanks are engaging the ground.

While it should be obvious, it may be mentioned here that air to supportoperation of the engines 59 and to supply the compressor means 61 passesinto the tanks 19 by way of the large duct and the openings 94 of theaxle 32.

While I have shown and described the apparatus as comprising the twogroups 15 and 16 of tanks and six tanks in each group, it should beunderstood that additional tanks may be employed in the groups ifpreferred,

and additional laterally spaced groups of tanks may also be used.

It is desired to emphasize that the forwardly tapering configuration ofthe float body portion, and the utilization of the toothed chains inconjunction with the tanks constitutes a very important feature of theinvention. This feature combined with the articulated construction ofthe float body portion afforded by the beams 26 and 27 renders theapparatus highly eflicient for breaking the ice and positivelypropelling itself during the ice breaking operation.

With my apparatus and method, the thickest ice encountered in navigablewaters can be broken quite readily with a mere fraction of theexpenditure required to break ice with conventional equipment, and in ashorter time and with a mere fraction of the manpower required tooperate and service the conventional equipment.

While the apparatus is illustrated largely in diagrammatic form in thedrawings, it will be apparent to those skilled in the art that theapparatus is quite simple and economical in construction, and can bebuilt largely from readily available commercial parts, and quiteeconomically.

It is to be understood that the form of the invention herewith shown anddescribed is to be taken as a preferred example of the same, and thatvarious changes in the shape, size and arrangement of parts may beresorted to, without departing from the spirit of the invention or thescope of the subjoined claims.

Having thus described my invention, I claim:

1. Ice breaking apparatus comprising a plurality of cylindrical tanksarranged in side-by-side relation to form a group of tanks, the tanks insaid group being successively smaller in diameter toward the forwardmosttank of the group, whereby said group of tanks forms a generallywedge-shaped float body portion, an axle rotatably supporting each tankof the group, freely articulated beam sections interconnecting saidaxles, a multiplicity of endless chains having teeth engaging theperipheries of the tanks in said group and having upper runs adapted tobe driven in unison in one direction, power operated means connectedwith at least one tank to rotate the same for causing rotation of theother tanks and movement of said chains, and means operable to floodselected tanks of the group with water to decrease their buoyancy and toforce the water therefrom at the will of an operator.

2. Ice breaking apparatus comprising a plurality of axles arranged inlaterally spaced parallel relation, freely articulated beam meansinterconnecting the ends of said axles, companion groups of tanksrotatably mounted upon said axles, the tanks of each group beingsuccessively smaller toward the forward end of the apparatus, endlessflexible toothed elements engaging the peripheries of the tanks in thegroups and having upper runs adapted to convey broken ice in onedirection and engageable with the bottom surface of the ice to be brokento positively propel the apparatus along the bottom of the ice, means toimpart rotation to at least one tank of each group, and transversedischarge conveyor means for the broken ice adjacent the rearmost tanksof the groups of tanks.

3. Ice breaking apparatus comprising a plurality of spaced parallelhollow axles, articulated beams secured to the ends of the axles tomaintain them in assembled relation and preventing rotation of theaxles, hollow cylindrical tanks freely rotatably mounted upon the axles,endless flexible toothed elements engaging the peripheries of said tanksand including upper runs forming a conveyor for broken ice, said upperruns engageable with the bottom surface of the ice to be broken forpositively propelling the apparatus along said bottom surface, poweroperated means to impart rotation to at least one of said tanks,transverse broken ice discharge means adjacent the rear end of saidapparatus, and means communicating with the interiors of said hollowaxles and tanks to create a partial vacuum within said tanks and tointroduce compressed air into the tanks, said last-named means operableto regulate the buoyancy of said tanks in the water.

4. A method of ice breaking comprising the steps of engaging the bottomof the ice with a buoyant structure which is shaped so that its buoyancyincreases as the structure moves further under the ice, and propellingsaid structure along the bottom of the ice until the buoyant forceexerted by the structure upon the ice is such that the ice breaksupwardly under bending stresses caused by said structure.

5. A method of breaking ice in navigable waters comprising the steps ofengaging the bottom of the ice with a generally wedge-shaped articulatedbuoyant structure whose buoyancy increases as the structure movesprogressively further under the ice, and propelling said buoyantstructure along the bottom of the ice by positive engagement of a movingpart of said structure with the ice until the ice cracks and breaksupwardly under flexure stress imparted by said buoyant structure, andcontinuing to propel said structure to thereby continuously break theice.

6. A method of ice breaking comprising engaging the bottom of the icewith a generally wedge-shaped articulated buoyant body portion whosebuoyancy increases as the body portion moves progressively furtherbeneath the ice, positively engaging the bottom of the ice withrearwardly moving elements having sharp projections to propel the bodyportion positively along the bottom of the ice, and continuing suchpropulsion of the structure until the buoyancy of the body portioncauses the ice to break upwardly under bending stresses imparted theretoby said body portion.

7. A method of ice breaking according to claim 6, and conveying thebroken ice upwardly and rearwardly upon said moving elements, anddischarging the broken ice to one side of the navigation channel formedby said method.

8. A method of ice breaking in navigable waters comprising engaging agenerally wedge-shaped float structure with the bottom of the ice andpositively propelling the wedge-shaped float structure progressivelyfurther under and along the bottom of the ice by engagement ofrearwardly moving pointed elements with the bottom of the ice and onsaid structure until the ice breaks upwardly due to bending stressesimparted thereto by the float structure.

9. A method of ice breaking comprising engaging the bottom of the ice,driving the engaging means in one direction while said means engages theice to force a buoyant body under the ice and thereby exerting anincreasing upward force upon the bottom of the ice, continuing saidaction until the ice breaks upwardly, and conveying away the broken iceand depositing the same upon one side of the channel opened by themethod.

10. A method of breaking ice in navigable waters comprising the steps ofpositioning the leading portion of a wedge-like articulated buoyantstructure beneath an edge portion of the ice, moving an upper part ofsaid structure rearwardly while said part frictionally engages thebottom of the ice to thereby propel said structure forwardly and cause awider portion of the structure to be drawn beneath the ice, therebyimparting to the ice an increasing upward thrust, continuing saidpropulsion until the ice breaks upwardly due to the buoyant forceimparted by said structure, and then conveying away the broken ice withsaid upper moving part of the structure and discharging the broken iceto one side of the navigation channel produced by the method.

11. Ice breaking apparatus comprising a plurality of cylindrical buoyanttanks arranged in side-by-side relation in a row with their axessubstantially parallel, the diameters of the tanks in said row varyingand being progressively smaller from the rearmost tank forwardly so thatsaid tanks form a generally wedge-shaped float structure, articulatedmeans interconnecting the ends of the tanks and holding them together insaid row, endless flexible elements having outwardly projecting teethengaging about the peripheries of said tanks and adapted to rotate thetanks in unison when driven, power operated means associated with onetank of the row of tanks to rotate such tank and thereby drive all ofthe flexible elements and rotate all of the tanks, and means to flood atleast some of the leading tanks with water and to introduce compressedair into all of said tanks.

12. A method of ice breaking comprising moving an elongated float bodyportion into initial engagement with the bottom surface of ice to bebroken, and propelling the float body portion along said bottom surfaceto gradually increase the total buoyancy force of the float body portionagainst said bottom surface until the ice breaks upwardly by flexure andcontinuing to propel the float body portion along said bottom surface toeffect continuous breaking of the ice by flexure.

13. A method of ice breaking comprising moving an articulated float bodyportion into adjacent relationship with ice to be broken, submerging aforward section of the float body portion and advancing it beneath theice, and then increasing the buoyancy of the submerged section to applyupward pressure against the ice to break it by flexure while continuingto propel the float body portion forwardly with respect to the ice.

14. A method of ice breaking comprising moving a wedge-like articulatedfloat body portion into adjacent relationship with the ice to be broken,submerging a forward section of the float body portion and advancing thesame beneath the ice, increasing the buoyancy of said submerged sectionto apply upward pressure against the ice to break it by flexure, andpropelling the float body portion along the bottom of the ice bypositive frictional engagement therewith.

15. Ice breaking apparatus comprising a crawler articulated float bodyportion including a plurality of articulated float units engageablebeneath the ice to be broken, and power means to advance the crawlerfloat body portion along the bottom surface of the ice for graduallyincreasing the upward force against the ice until the ice breaksupwardly by flexure.

16. Ice breaking apparatus comprising a forwardly tapering freelyarticulated float body portion adapted to have its leading end engagedbeneath the ice to be broken, rearwardly moving propulsion and brokenice conveyor means carried by the top of said tapering articulated floatbody portion and directly engaging the bottom surface of the ice topositively propel the tapering float body portion along the bottomsurface of the ice and to thereby gradually increase upward thrust uponthe ice until the ice breaks under bending stress, said propulsion andconveyor means then conveying the broken ice upwardly and rearwardlyupon the articulated float body portion, and power operated means tooperate said propulsion and conveyor means.

17. Ice breaking apparatus comprising a freely articulated forwardlytapering float body portion adapted to have its leading end engage underthe ice to be broken, combined endless propulsion and broken iceconveyor means surrounding said tapering articulated float body portionand including an upper run which moves rearwardly and adapted todirectly engage the bottom surface of the ice to positively propel thefloat body portion along the bottom surface of the ice and therebygradually increasing 5 the upward thrust upon the ice until the icebreaks upwardly under bending stress, said combined means then conveyingthe broken ice upwardly and rearwardly upon said float body portionwhile contining to propel the float body portion along the bottomsurface of the ice, and 10 means to continuously operate said combinedmeans.

References Cited in the file of this patent UNITED STATES PATENTS EllisFeb. 5, 1924 Hill June 16, 1959 FOREIGN PATENTS Germany Jan. 28, 1891Germany Aug. 18, 1955

